What does the Amtax sc analyser actually measure?
Amtax sc Measurements
When the measurement is displayed, the units are "NH4-N" or "NH4", which means that the instrument measurement is expressed as ammonium and reports the values as Nitrogen (also described as "NH4 as N") or as Ammonium. The AMTAX sc analyser adds Sodium Hydroxide (NaOH) to adjust the pH and convert ammonium ions (NH4+) to gaseous Ammonia (NH3) which passes through an Ammonia gas selective membrane and causes a pH shift of an electrolyte solution. This pH shift in the electrolyte is measured as a mV signal that is proportional to the concentration of Ammonia (NH3) in the sample. (The AMTAX sc can be configured to report as NH4 in the LOCATION1 (and/or LOCATION2 in a dual stream unit) SET PARAMETER to Ammonium (NH4) instead of Ammonium-Nitrogen (NH4-N)).